Precast concrete threaded pilings

Abstract

A reinforced concrete threaded pile provides a generally conically shaped tapered concrete pile member which is provided with a metallic reinforcement core for carrying the torsional and tensile forces created in the pile during its insertion. A metallic head is provided at, for example, the upper portion of the pile, which provides a point for the connection of a sufficient torsional driving force thereto for insertion of the pile. The head member can be metallic, and is substantially integrally connected to the reinforcement core, so that the torsional forces can be developed through the head and the reinforcement core such that torsional and tensile forces are not carried by the concrete to a degree which would cause a failure of the concrete by cracking. The concrete body is provided with an outer surface of spiral threads which has a relatively minor thread pitch that provides for relatively easy insertion of the pile into the desired soil medium and is mechanically compatible therewith. If desired, reinforcement can be provided in the threads. The threads are equally spaced, and a female "soil socket" is formed upon insertion of the pile into the earth, the spiral tapered pile gradually expanding and compacting the surrounding soil as the equally spaced threads push the pile downward.

I claim: 
     
       1. A precast, threaded, concrete pile, comprising: (a) a metallic upper portion providing connection means for the application of rotational driving force thereto for driving the pile down into the ground by rotating it;   (b) a metallic reinforcement core integrally connected to said upper portion extending at least substantially down the full length of the pile; and   (c) a generally circular shaped longitudinally extended, cementitious body precast about and embedding said core, said body having an outer surface provided with only a single continuous set of substantially equally spaced spiral screw threads along at least substantially the entire length thereof; whereby, in being rotatably driven at the head, the reinforcing core of the pile rather than the concrete directly carries the torsional and tensile forces created in the pile during its insertion.   
     
     
       2. The concrete pile of claim 1, wherein said threads have a relatively minor thread pitch providing a projecting surface of a relatively slight angle with the vertical for engaging and bearing against the soil into which the pile is inserted, the relatively minor thread pitch being mechanically compatible with the soil into which the pile is inserted, a reduced torsional stress being experienced by the pile. 
     
     
       3. The concrete pile of claim 2, wherein there is provided about six (6) or more of said threads per foot of pile length. 
     
     
       4. The concrete pile of claim 1, wherein said core is comprised of: i. a plurality of longitudinally extending, high strength reinforcing bars, each integrally connected to said upper portion and extending down substantially the full length of said body;   ii. a plurality of longitudinally spaced reinforcing collars, each of said collars being integrally connected to said longitudinally extending reinforcing bars; and   iii. at least one spiral reinforcing element, said spiral reinforcing element having a pitch at least generally similar to the pitch of said screw threads.   
     
     
       5. The concrete pile of claim 4, wherein said collars decrease in diameter from the top to the tip of the pile. 
     
     
       6. The concrete pile of claim 1, wherein said core is comprised of a longitudinally extended bar extending down the center-line of the pile substantially the full length of said body and a plurality of longitudinally spaced, laterally extending arms attached to said bar. 
     
     
       7. The concrete pile of claim 1, wherein said upper portion forms a head having at least four, equal, vertical sides for receiving driving socket tools to impart a rotational torque to the head. 
     
     
       8. The concrete pile of claim 7, wherein the head is constructed as a piece of solid material. 
     
     
       9. The concrete pile of claim 7, wherein the head is constructed as a metal sleeve connected to the core. 
     
     
       10. The concrete pile of claim 7, wherein the head is constructed as a framework connected to the core and embedded in a solid mass. 
     
     
       11. The concrete pile of claim 1, wherein said upper portion is provided with transverse through-hole means arranged for receiving a leverage bar to impart rotational torque to the head. 
     
     
       12. An extendible, reinforced, precast concrete pile system comprising: (a) at least two, spiral threaded, precast pile sections placeable and connectable in line together, each of said pile sections being threaded along at least substantially its entire length with only a single, continuous set of threads of at least substantially the same pitch as that of the adjacent section;   (b) a reinforcement core provided in each pile section, each of said cores comprising at least one longitudinally extending reinforcement bar and at least one laterally extending member, each of said members being integrally connected to said longitudinal bar; and   (c) connector means associated with said pair of pile sections for attaching said pile sections together for concurrent rotation with one another.   
     
     
       13. The system of claim 12, wherein said threads have a relatively minor thread pitch providing a projecting surface of a relatively slight angle with the vertical for engaging and bearing against the soil into which said pile is inserted, the relatively minor thread pitch being mechanically compatible with the soil into which the pile is inserted. 
     
     
       14. The system of claim 13, wherein there is provided about six (6) or more of said threads per foot of pile length. 
     
     
       15. The system of claim 12, wherein said connector means are metallic, and said bar and said connector means are integrally attached together within each of the pile sections. 
     
     
       16. The system of claim 12, wherein said connector means comprises a socket on one of said pile sections and a corresponding interlocking projection on the other of said pile section, said socket and said projection each being provided with a proximate metallic reinforcing member, said reinforcing member being connected to said core. 
     
     
       17. The system of claim 16, wherein said connector means is comprised of a socket on each of said pile sections and an interlocking structural key, said key having projections for attaching said key to each of said sockets to form a connection, and each of said sockets is provided with a proximate metallic reinforcing member, said reinforcing member being connected to said core. 
     
     
       18. The system of claim 12 wherein the end portion of each section adjacent said connector means is provided with feathered threads, with the connection of said sections providing a uniform, equally spaced, continuous thread pitch throughout the area adjacent said connector means. 
     
     
       19. The system as defined in claim 17, wherein the key is a length of rod provided with a plurality of splines. 
     
     
       20. A system as defined in claim 12, wherein said connector means includes a plurality of opposed sockets provided in each of the sections and arranged for receiving a like number of keys associated with the sockets. 
     
     
       21. A method for installing a concrete pile into a soil medium comprising the steps of: a. providing a first reinforced concrete pile member, said pile comprising: i. a metallic reinforcement core; ii. an upper metallic driving attachment connected to said core; and iii. a tapered concrete substantially conical mass cast symmetrically about said core for rotation therewith; the tapered concrete mass being provided with an equally spaced spiral thread structure from substantially top to tip; b. orienting the pile member in a substantially erect position; and c. applying rotational force to said driving attachment without direct driving engagement with said concrete mass to rotationally drive the pile member into the ground.   
     
     
       22. The method of clam 21, wherein there is provided the further step of applying a lubricating agent to at least a part of the pile member. 
     
     
       23. The method of claim 21, wherein there is provided the further step of applying water to at least a part of the pile member. 
     
     
       24. The method of claim 21, wherein there is provided the further step "d" of forming with the pile member a compacted female thread soil socket in the soil medium; the soil socket having a thread pitch equal to the thread pitch of the pile member. 
     
     
       25. The method of claim 24, wherein in step "d", each thread member laterally displaces a portion of the adjacent soil medium away from the pile member as the pile is rotated by the applied rotational force. 
     
     
       26. The method of claim 21, further comprising the step of rotating the pile member until its insertion into the soil medium places the pile member's uppermost portion at the soil surface. 
     
     
       27. The method of claim 26, comprising the further steps of providing a second pile member of substantially constant diameter; structurally connecting the first and second pile members; and applying rotational force to the second pile member. 
     
     
       28. A method for installing a concrete pile into a soil medium comprising the steps of: a. providing a first reinforced concrete pile member, said first pile member comprising: i. a metallic reinforcement core;   ii. an upper metallic driving attachment connected to the core; and   iii. a tapered concrete substantially conical mass cast symmetrically about said core for rotation therewith, the tapered concrete mass being provided with an equally spaced thread structure from substantially top to tip.     b. providing a second reinforced concrete pile member, said second pile member comprising: i. a metallic reinforcement core; and   ii. a concrete mass cast about said core for rotation therewith,     c. providing a connection means on each of the pile members for structurally joining the first and second members together;   d. orienting the first pile member in an erect position;   e. applying rotational force to the first pile member until its upper portion is adjacent the surface of the soil medium;   f. connecting the first and second pile members together; and   g. applying rotational force to the second pile member.   
     
     
       29. The method of claim 27, wherein there is further provided the step of forming with the first pile member a compacted female thread soil-socket in the soil medium, the soil socket having a thread pitch equal to the thread pitch of the pile member. 
     
     
       30. The method of claim 28 wherein there is provided the further step of adding additional constant diameter pile sections to the previous uppermost pile section as the upper surface of the previous uppermost pile section nears the surface of the soil medium. 
     
     
       31. The concrete pile of claim 1 wherein said body is tapered down from a maximum diameter at the top to a minimum diameter at its bottom, forming a generally conical shape. 
     
     
       32. The concrete pile of claim 1, wherein said body is at least generally cylindrically shaped, having at least generally a constant diameter along its length.